Investigation of the block toppling evolution of a layered model slope by centrifuge test and discrete element modeling

• Published in: Journal of Rock Mechanics and Geotechnical Engineering Vol. 16; no. 1; pp. 112 - 122
• Main Authors: Jin, Leilei, Dong, Hongkai, Ye, Fei, Wei, Yufeng, Liu, Jianfeng, Wang, Changkui
• Format: Journal Article
• Language: English
• Published: State Key Laboratory of Hydraulic and Mountain River Engineering,College of Water Resource and Hydropower,Sichuan University,Chengdu,610065,China%State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu,610059,China 01.01.2024; Elsevier
• Subjects: Anti-dip slope; Block toppling; Centrifuge; Discrete element method; Failure mechanism; Block toppling; Centrifuge; Failure mechanism; Discrete element method; Anti-dip slope
• ISSN: 1674-7755
• DOI: 10.1016/j.jrmge.2023.02.019

Primary toppling usually occurs in layered rock slopes with large anti-dip angles.In this paper,the block toppling evolution was explored using a large-scale centrifuge system.Each block column in the layered model slope was made of cement mortar.Some artificial cracks perpendicular to the block column were prefabricated.Strain gages,displacement gages,and high-speed camera measurements were employed to monitor the deformation and failure processes of the model slope.The centrifuge test results show that the block toppling evolution can be divided into seven stages,i.e.layer compression,formation of major tensile crack,reverse bending of the block column,closure of major tensile crack,strong bending of the block column,formation of failure zone,and complete failure.Block toppling is characterized by sudden large deformation and occurs in stages.The wedge-shaped cracks in the model incline towards the slope.Experimental observations show that block toppling is mainly caused by bending failure rather than by shear failure.The tensile strength also plays a key factor in the evolution of block toppling.The simulation results from discrete element method(DEM)is in line with the testing results.Tensile stress exists at the backside of rock column during toppling deformation.Stress concentration results in the fragmented rock column and its degree is the most significant at the slope toe.